Application the reliability design theory and methods basis on random-fuzzy probability model,it is quantitative analyzed that reliability range of virgin critical strength in buckling of cylinder during pressure test and normal operation.

The researching results show that: DFor the fuzzy reliability range of critical strength in buckling for steel thinness wall cylinder, the range should be 0.

Fuzzy reliability design of random stress intensity of pressure vessels;

Detail information of stress analysis process and evaluation principle for vertical slender vessel producing polyurethane were given,illustration of some key problems in the process of applying load was made and model for finite element analysis was set up,results calculated by ANSYS under different working conditions were given and the stress intensity was checked.

The research of the relationship between the accumulation of the acoustic emission signal formed in the plastic zone of the crack tip and stress intensity factor is conducted.

Evaluation on the Stress Strength at the Junction Area between the Cylinder of an Internal Pressure Vessel and Its Big Nozzle

That is when the difference of the intension-stress and stabilization-stress is bigger,the component is wrecked for lose- stabilization.